A livestock manager needs to know the level of moisture in feed so that the manager knows the true amount of nutrition being fed. That is, particularly relating to the feeding of forages to livestock, feeding cannot be done simply on the basis of the weight of the feed being fed. Moisture content has a substantial impact on the weight of feed, but no impact on the nutrition of the feed. The amount of feed to mix and feed to livestock is determined by the DMI (Dry Matter Intake) of the feed. In addition, farm managers would like to know the DMI of all field harvested commodities to determine total tonnage of harvest.
Measuring the moisture content of forages with a near infrared (NIR) spectrometer is not new, but there are many disadvantages to the current methods and apparatus being used. Most livestock managers today use one of the three methods below for measuring the moisture content.
A. Weighing the forage material wet, then drying the material and weighing it again. This is the method employed in the use of a Koster Tester. Based on the difference in weight, one can calculate the percentage of moisture that was in the original forage material. This process typically takes 30-45 minutes, and the reliability is based upon the ability of the operator to take a representative sample of the forage, as opposed to the dried out material at the top or exposed area of a collection of forage. In addition, volatiles other than water can be driven off during the drying process, resulting in inaccurate water moisture results.
B. Using a spectrum analyzer for moisture and other constituents, such as proteins, starches, etc. The disadvantage here is that a spectrum analyzer typically costs in the range of $10,000-$20,000 or more, and the operator may not be interested in those other constituents.
C. Sending samples to a laboratory. This method can be lower in cost, but is slow, normally taking days to get results.
Clearly, a better method and apparatus are needed to properly sense the moisture in animal feeds, so that a livestock manager can quickly (in seconds), easily, inexpensively and accurately determine the dry matter intake of the feed being fed to the livestock.